BAS Paper Respondent Guide

Boundary Annexation Survey (BAS)
Respondent Guide: Paper
Instructions for Participating in the 2021 Boundary and Annexation Survey
Revised as of October 08, 2020

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Boundary Annexation Survey (BAS) Respondent Guide: Paper

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TABLE OF CONTENTS
Introduction ........................................................................................................................... vi
A.

The Boundary and Annexation Survey .......................................................................... vi

B.

Key Dates for BAS Respondents .................................................................................... vi

C.

BAS State Agreements.................................................................................................. vii

D.

Legal Disputes .............................................................................................................. vii

Part 1

Completing the BAS Forms .................................................................................... 1
Forms Included in the BAS Package................................................................................ 1
Name or Type Changes .................................................................................................. 1
Contact Information ....................................................................................................... 1
Legal Boundary Changes ................................................................................................ 1
Other Changes................................................................................................................ 1

Part 2

Census Bureau Geocoding ..................................................................................... 2
MAF Structure Point (MSP) Geocoding .......................................................................... 2

2.2 Address Range Geocoding .............................................................................................. 3
Part 3

Reviewing and Updating BAS Maps ....................................................................... 4
Maps Included in the BAS Package ................................................................................. 4
Requesting Additional Maps .......................................................................................... 4
Reviewing Boundaries with Imagery in TIGERweb ......................................................... 4
General Guidelines for Reviewing and Updating BAS Maps ........................................... 4
Legal Boundary Changes ................................................................................................ 5

3.5.1 How to Draw Legal Boundary Changes ...................................................................... 5
3.5.2 Boundary Changes Involving Coincident Features ..................................................... 6
3.5.3 Boundary Corrections ................................................................................................ 7
3.5.4 Geographic Corridors and Offsets .............................................................................. 8
3.5.4.1 Geographic Corridors ........................................................................................................................8
3.5.4.2 Geographic Offsets..........................................................................................................................10

3.5.5 New Incorporations ................................................................................................. 11
3.5.6 Disincorporations..................................................................................................... 11
3.5.7 Tribal Subdivisions ................................................................................................... 12
3.5.7.1 Tribal Subdivision Program Procedures ..........................................................................................13
3.5.7.2 Updating Existing Tribal Subdivisions..............................................................................................13
3.5.7.3 Tribal Subdivision Documentation ..................................................................................................14
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3.5.8 County Review and Consolidations .......................................................................... 14
3.5.9 Public Land Survey System....................................................................................... 14
Part 4

Feature Modifications ......................................................................................... 15
Modifying Locations of Streets ..................................................................................... 15

4.1.1 Adding Streets ......................................................................................................... 16
4.1.2 Adding Street Names in a Congested Area .............................................................. 16
4.1.3 Correcting Street Names.......................................................................................... 17
4.1.4 Deleting Streets ....................................................................................................... 17
4.1.5 Labeling Unnamed Streets ....................................................................................... 17
4.1.6 Adding Cul-De-Sacs or Circles .................................................................................. 18
Annotating Address Range ........................................................................................... 18
4.2.1 When Adding Address Ranges ................................................................................. 18
Point Landmarks........................................................................................................... 18
Area Landmarks ........................................................................................................... 19
Part 5

Returning Updates to the Census Bureau ............................................................ 20

Appendices ............................................................................................................................ 21
Appendix A

Additional Documentation of Changes Forms ................................................ A-1

A1

Places ......................................................................................................................... A-1

A2

Counties and Equivalent Areas ................................................................................... A-2

A3

Minor Civil Divisions ................................................................................................... A-3

A4

Reservations and Off-Reservation Trust Land ............................................................ A-4

Appendix B

MTFCC Descriptions ....................................................................................... B-1

Appendix C

Reading a Map ............................................................................................... C-1

C1

Index Maps ..................................................................................................................C-1

C2

Parent Maps ................................................................................................................C-2

C3

Inset Maps...................................................................................................................C-3

C4

Scales ..........................................................................................................................C-4

C5

Compass Rose .............................................................................................................C-5

C6

Legend .........................................................................................................................C-6

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LIST OF FIGURES
Figure 1. GPS Method of Geocoding ............................................................................................. 2
Figure 2. Address Range Method of Geocoding ............................................................................ 3
Figure 3. Shared Boundary ............................................................................................................ 5
Figure 4. Correctly Annotating a Legal Boundary Change ............................................................. 5
Figure 5. Correctly Annotating an AIA Trust Land ......................................................................... 6
Figure 6. Annotating a Legal Boundary Change............................................................................. 7
Figure 7. Annotating a Legal Change to an Incorporated Place ..................................................... 7
Figure 8. Annotating a Boundary Correction to an Incorporated Place Boundary ....................... 8
Figure 9. Geographic Corridor and Geographic Offset .................................................................. 8
Figure 10. Where the Right-of-way Belongs in the Unincorporated Area ..................................... 9
Figure 11. Housing Units in the Unincorporated Area................................................................... 9
Figure 12. Indicating a Geographic Corridor by Using a Red Pencil ............................................. 10
Figure 13. (Left) The Place Boundary is Along the Front-lot-line ................................................. 11
Figure 14. (Right) The Place Boundary is on the Rear-lot-line ..................................................... 11
Figure 15. Depicting a Geographic Offset on a Paper Submission ............................................... 11
Figure 16. Recording New Tribal Subdivision Information .......................................................... 13
Figure 17. Modifying a Street Feature, No Boundary Movement ............................................... 15
Figure 18. Modifying a Street Feature with Boundary Movement .............................................. 15
Figure 19. Adding an MTFCC Code When Adding a New Street .................................................. 16
Figure 20. Adding Street Name Features in a Congested Area When Adding Streets ................. 16
Figure 21. Correcting a Street Name ........................................................................................... 17
Figure 22. Deleting a Street Feature ........................................................................................... 17
Figure 23. Adding Unnamed Road Features ................................................................................ 17
Figure 24. Adding Cul-de-sac and Circle Features ....................................................................... 18
Figure 25. Adding Street Feature/Annotating with Name and Address Breaks .......................... 18
Figure 26. Adding a Point Landmark ........................................................................................... 19
Figure 27. Adding an Area Landmark .......................................................................................... 19
Figure 29. Index Map .................................................................................................................C-1
Figure 30. The Parent Map .........................................................................................................C-2
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Figure 31. The Key to Adjacent Sheets .......................................................................................C-3
Figure 32. The Sheet Location within Government key..............................................................C-3
Figure 33. An Inset Map as it is Displayed on the Index Map .....................................................C-4
Figure 34. Inset Maps .................................................................................................................C-4
Figure 35. Bar Scale ....................................................................................................................C-5
Figure 36. Large Scale Map ........................................................................................................C-5
Figure 37. Compass Rose ...........................................................................................................C-5
Figure 38. Legend Describing What Each Symbol Means ...........................................................C-6
Figure 39. Map Depicting Multiple Features Concurrently ........................................................C-7

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INTRODUCTION
A.

The Boundary and Annexation Survey

The U.S. Census Bureau conducts the Boundary and Annexation Survey (BAS) annually to collect
information about selected legally defined geographic areas, such as counties (and equivalent
areas), incorporated places, minor civil divisions (MCDs), federally recognized American Indian
Areas (AIAs) — including reservations, off-reservation trust lands and tribal subdivisions, and
Hawaiian Homelands. BAS also provides an opportunity for participants to review the names
and geographic relationships for these areas. Title 13, Section 6, United States Code authorizes
this survey.
The Census Bureau uses the boundary information collected during BAS to tabulate data for the
decennial and economic censuses, and to support the yearly delivery of the Population
Estimates Program (PEP) and the American Community Survey (ACS) data. Maintaining correct
boundaries and boundary-to-feature relationships through BAS helps ensure that the Census
Bureau assigns the appropriate housing and population counts to each government.
In compliance with the Office of Management and Budget Circular A-16, BAS supports the
Census Bureau’s spatial data steward responsibilities for the Federal Geographic Data
Committee (FGDC) and the Geospatial One-Stop by updating the inventory and boundaries of
governments.
In addition, BAS is the source of up-to-date information on changes to the boundaries, codes
and names of incorporated places, MCDs, counties (and equivalent areas), Hawaiian
Homelands, and federally recognized AIAs, which include reservations and off-reservation trust
lands used by the U.S. Geological Survey (USGS), the National Map, and the Geographic Names
Information System (GNIS). Please visit the BAS program website at
.
For more information on BAS, please view the BAS video series on the Census Bureau’s BAS
website at .

B.

Key Dates for BAS Respondents

January 1—Boundary changes must be legally in effect on or before this date to be reported in
the current survey year.
March 1—Boundary updates returned by this date will be reflected in the ACS and PEP data,
and in next year’s BAS materials.
May 31—Boundary updates returned by this date will be reflected in next year’s BAS materials.

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C.

BAS State Agreements

The Census Bureau has established a number of agreements with states for reporting boundary
changes. Please visit the BAS State Agreements webpage within the BAS program website at
or call
1-800-972-5651 for information regarding state agreements.
Note:

D.

The Census Bureau can only establish BAS state agreements for states that require local
governments to report boundary changes to a state agency.

Legal Disputes

If the Census Bureau discovers that an area of land is in dispute between two or more
jurisdictions, the Census Bureau will not make any boundary corrections until the parties come
to a written agreement, or there is a documented final court decision regarding the dispute.
To learn more, please contact the Census Bureau Legal Office at 1-301-763-9844.
For disputes involving tribal areas, the Census Bureau must defer to the Office of the Solicitor at
the Department of the Interior for a legal opinion. Often complicated land issues require an
extended period of time for resolution, and in those cases, the Census Bureau will retain the
current boundary in the database until a legal opinion is issued by the Solicitor's office.

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PART 1

COMPLETING THE BAS FORMS

Forms Included in the BAS Package
The forms in the BAS package should be used to verify legal names, legal status, contact
information, previous legal boundary changes submitted to the Census Bureau, and to
document any recent or missing legal boundary changes. There are four types of forms:
1.
2.
3.
4.

BAS-1 for Incorporated Places.
BAS-2 for Counties and Equivalent Areas.
BAS-3 for Minor Civil Divisions (MCDs).
BAS-5 for American Indian Reservations and Off-Reservation Trust Land.

Name or Type Changes
Please verify that the legal name and legal status of the government or AIA are accurate. Make
any necessary corrections by crossing out the error and clearly printing the correct information.
Provide an effective date for name, type, or status changes. County participants should verify
the list of active and inactive entities within their counties.

Contact Information
Please verify that the Census Bureau has the most recent BAS, HEO, or Tribal Chief (TC) contact
information for the government or AIA. Fill in any missing or incorrect information, especially
blank email addresses. If the primary address of the BAS contact, HEO, or TC is a PO Box,
provide the Census Bureau with a physical address that can be used for the delivery of maps.
Contact changes or updates may also be provided to the Census Bureau throughout the year by
email to .

Legal Boundary Changes
Please record all legal boundary changes in the Documentation of Changes section of the BAS
form. Include legal boundary changes that occurred prior to January 1 of the current survey
year if they do not appear on the current BAS maps. Please include legal authorization, such as
a local ordinance or resolution number, and the effective date of the legal action. If additional
pages are needed to record legal changes, a copy of the Documentation of Changes is provided
in the appendix.

Other Changes
Please indicate if there are any boundary corrections or feature updates that need to be made
on the BAS maps. This will assist the Census Bureau in identifying and accounting for any
updates made to the maps.

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PART 2

CENSUS BUREAU GEOCODING

Geocoding is how the Census Bureau codes the location of the population within the legal
boundaries of a geographic area. There are two primary methods of geocoding used by the
Census Bureau, and both of these involve coding an address to a spatial polygon. One uses
Global Positioning System (GPS) technology to create a Master Address File (MAF) structure
point (MSP) and the other uses address ranges for geocoding.

MAF Structure Point (MSP) Geocoding
A field worker stands in front of a house or living quarters, and records the physical location
with a GPS device (Figure 1). Usually, the GPS point should fall very close to the front door of
the house. However, since GPS points are collected in the field, real-world obstacles like locked
fences, poor satellite reception, or even aggressive dogs might sometimes prevent the worker
from gaining access to the front door. In these circumstances, the worker may have to take the
GPS coordinate from the sidewalk or side of the road.

Figure 1. GPS Method of Geocoding
Notice that it is occasionally not possible for the field worker to go all the
way to the front door, due to unforeseen circumstances, like the fence or
the dog shown above. Thus, the MSP (represented by the red pins) can
sometimes fall within the road or the road right-of-way.

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2.2

Address Range Geocoding

When no MSP is available, the Census Bureau codes houses and living quarters according to a
potential range of addresses associated with the adjacent stretch of road (Figure 2).

Figure 2. Address Range Method of Geocoding
When it is not possible to collect an MSP, houses are geocoded according to
their placement along a range of potential addresses along that road. Since
the address has a relationship with the road, boundaries placed on frontlot-lines will lead to mis-geocoding unless an offset flag is used.

While the two methods of geocoding differ greatly, both rely heavily on the integrated nature
of the Master Address File/Topologically Integrated Geographic Encoding and Referencing
(MAF/TIGER) system. These geocoding methods are affected by the way streets and boundaries
are represented in relation to one another. This interdependence between streets, boundaries,
and geocoding means that Census Bureau representations of legal boundaries may sometimes
differ from other representations (e.g., in local or state GIS). This is especially true regarding
geographic corridors and offsets that follow road right of ways (or the front-lot-lines of parcels).
In both of the examples above, delineating a boundary along the front-lot-line will tend to
increase the risk of incorrect geocoding. As a result, using the road centerline as a boundary is
the safer method.
When completing a BAS submission in which a road or road right-of-way is owned or
maintained by a place or AIA but the adjacent housing is not, the respondent should use the
centerline of the road (not the front-lot-line) as the boundary whenever possible. If local or
state law requires the use of the front-lot-line boundary, the respondent must explicitly
designate the polygon(s) between the road centerline and the front-lot-boundary as a corridor
or an offset (see 3.5.4, Geographic Corridors and Offsets of this document for more details).

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PART 3

REVIEWING AND UPDATING BAS MAPS

Maps Included in the BAS Package
The Census Bureau mails an index map showing the entire government or AIA, along with more
detailed individual map sheets. Index maps are provided as a reference to help locate a map
sheet. Governments and AIAs with more than 30 map sheets receive only an index map and the
map sheets that show the boundary ring. Governments that require more than 30 boundary
ring map sheets receive only the index map. Please review Appendix Cfor a further description
of the map types.

Requesting Additional Maps
If an individual map sheet or full set of maps was not provided for a county, incorporated
place, MCD, or AIA where boundary changes or feature updates need to be made, please call
1-800-972-5651 or email to request the additional materials. Do not
make updates on the index map.

Reviewing Boundaries with Imagery in TIGERweb
Governments that have requested paper maps can use TIGERweb
for a more detailed
version of their boundaries with imagery before annotating the paper maps. Instructions for
using TIGERweb for BAS can be found on the BAS website at
.

General Guidelines for Reviewing and Updating BAS Maps
1. Colored pencils are provided in the package. The red pencil should be used to indicate legal
boundary changes and non-legal boundary corrections for all counties, places, MCDs, and AIAs.
The purple pencil should be used to indicate feature changes or corrections. The blue pencil
should be used by AIAs to add or modify tribal subdivisions.
2. Compare the BAS maps to a local source for a government (e.g., a local plat map, or a county
assessor’s dataset). Update the map(s) if the boundaries shown do not correctly depict the
boundaries in effect as of January 1 of the current survey year.
3. Annexations and deannexations from previous years may be provided in addition to updates in
effect as of January 1; however, the Census Bureau does require legal documentation when
submitting these legal updates.
4. The maps show boundaries for multiple legal and statistical boundaries. If a government’s legal
boundaries are coextensive with another boundary, the symbols on the map will alternate. In
Figure 3 the county shares a boundary with an incorporated place and Census Designated Place
(CDP); therefore, the symbols on the map alternate between county, incorporated place, and
CDP.

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Figure 3. Shared Boundary
The combined line represents a county, incorporated place, and CDP
boundary.

Legal Boundary Changes
Legal boundary changes are the result of legal actions (e.g., annexations), and documenting
such changes is the primary goal of the BAS. AIA legal documentation (e.g., statute, federal
court decision, trust deed) must accompany all AIA legal boundary changes, while legal
boundary change submissions from incorporated places, MCDs, and counties must provide an
authorization number, such as a resolution or ordinance number1, and the effective date.

3.5.1

How to Draw Legal Boundary Changes

Figure 4 and Figure 5 illustrate the correct way to draw legal boundary changes on BAS maps.
•
•
•
•

Using the red pencil provided, cross out the portion of the boundary that is no longer current
with a string of “Xs”.
Draw the new boundary line(s) ensuring the boundary is closed.
Add the ordinance number or other legal identifier of the action authorizing the change, along
with the effective date of each annexation or deannexation that is drawn on the map.
Record all legal changes in the Documentation of Changes section of the BAS form.

Figure 4. Correctly Annotating a Legal Boundary Change
Draw “Xs” with the red pencil and record the changes in the Documentation
of Changes section of the BAS form.

1

Legal boundary changes from the State of Georgia are the exception: a state statute requires participants to
include acreage, and the Census Bureau requests that the respondent includes an authorization number.
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Figure 5. Correctly Annotating an AIA Trust Land
Correctly annotate an AIA trust land and record the change in the
Documentation of Changes section of the BAS form. The original reservation
is not deleted and therefore does not require a string of “Xs”.

3.5.2

Boundary Changes Involving Coincident Features

Figure 6 and Figure 7 illustrate how to adjust a boundary that is coincident with
(i.e., follows exactly) a feature, such as a river or street. In this case, the feature location is
correct, but the boundary location is incorrect.
•
•
•
•

Using the red pencil, cross out the portion of the boundary that is no longer current using a
string of “Xs” inside circles.
Draw the updated boundary.
Add the authorization number or other identifier of the action authorizing the change along
with the effective date of each addition or deletion.
Record all legal changes in the Documentation of Changes section of the BAS form.

If both the boundary and feature need to be moved, cross out the incorrect boundary with a
string of red “Xs” and then draw a red line representing the new location of the boundary and
road.
Figure 6 shows a change to the boundary where only the boundary moves as well as the
accompanying Documentation of Changes form excerpt. Similarly, the left image of Figure 7
illustrates a change where only the boundary moves, but the right image shows a boundary
change where the associated feature moves along with the boundary. If these changes are the
result of an annexation or deannexation, include the authorization number and effective date.

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Figure 6. Annotating a Legal Boundary Change
Annotating a legal boundary change coincident with a river feature, where
the river location does not change, but the boundary does. The legal change
is also recorded in the Documentation of Changes.

Figure 7. Annotating a Legal Change to an Incorporated Place
Annotating a legal change to an incorporated place boundary coincident
with a road feature. The legal change is recorded in the Documentation of
Changes. Left: Only the boundary moves to the new location. The street
feature location is correct, but the boundary location is incorrect. Right:
Both the boundary and the street feature move to a new location. Both the
boundary and the street feature location are incorrect.

3.5.3

Boundary Corrections

A boundary correction is the adjustment of a boundary to correct an error in how the Census
Bureau depicts an existing boundary. Boundary corrections should follow the general shape of
the existing boundary. Legal documentation is not required when submitting a boundary
correction to the Census Bureau. Boundary corrections also do not need to be reported on the
Documentation of Changes BAS form. Figure 8 illustrates how to complete a boundary
correction.
•
•
•

Using the red pencil, cross out the incorrect boundary with a string of “Xs”.
Add a line showing the correct boundary.
Print the letters BC inside the change to identify the update as a boundary correction rather
than a legal change.

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Figure 8. Annotating a Boundary Correction to an
Incorporated Place Boundary

3.5.4

Geographic Corridors and Offsets

3.5.4.1 Geographic Corridors
Figure 9 shows a corridor that has been created where the incorporated place or AIA owns the
right-of-way, and wishes for that ownership to be displayed on the Census Bureau’s maps, but
the housing units are not included in the incorporated place or AIA (shown in color). Without a
corridor, the housing units along this road would be incorrectly geocoded into the incorporated
place or AIA. Thus, if it is important to the place or AIA that its ownership and/or maintenance
of the road and/or its right-of-ways be displayed on Census Bureaus’ maps, a geographic
corridor should be created. However, the Census Bureau does not require places and AIAs to
report right-of-ways; maintaining geographic corridors in a nationwide database is not essential
to the mission of the Census Bureau and the right-of-way should only be included if it is crucial
to the place or AIA, or if state or local laws require it.

Figure 9. Geographic Corridor and Geographic Offset
The image on the left illustrates a geographic corridor (Co Rd, south of
Samples Rd) and a geographic offset (Co Rd, north of Samples Rd). The
geographic corridor and offset are both part of the incorporated place
(yellow area), but dwelling units are not. The image on the right illustrates a
geographic offset, designated by red diagonal lines. The offset is part of the
incorporated place (green area). However, the dwelling units are counted
outside of the incorporated place.

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Figure 10 below shows a case where the right-of-way belongs in the unincorporated area, while
the housing units in Figure 11 are included in the incorporated place (shown in color). While
depicting this corridor may be important for local purposes, it is not relevant for Census Bureau
tabulations because no house can be built in a road right-of-way. This type of corridor should
not be included in a BAS response.
Please note that the Census Bureau does not require places or AIAs to display right-of-ways or
road maintenance corridors that do not contain or potentially contain housing or population. If
local or state law does not require depiction of these geographic features, the Census Bureau
prefers that they be left off BAS submissions. If it is necessary for the place or AIA to depict
them, they must be submitted as a geographic corridor.

Figure 10. Where the Right-of-way Belongs in the Unincorporated Area
Figure 11. Housing Units in the Unincorporated Area

Geographic corridors can be provided to the Census Bureau if the centerline representation
results in addresses being assigned to the wrong government. However, geographic corridors
should only be created if the addresses along the street do not belong to the participant’s
government. To indicate a geographic corridor on the map, use the red pencil to draw a line on
each side of the road. Mark the beginning and end of each line with perpendicular hatch (//)
marks. Write the letters “GC” beside each line (Figure 12). To remove a geographic corridor or
offset, use the red pencil to mark the beginning and end of the corridor or offset with
perpendicular hatch (||) marks and write “remove GC.”

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Figure 12. Indicating a Geographic Corridor by Using a Red Pencil
To indicate a geographic corridor on the BAS return, use the red pencil to
draw a line on each side of the road. Mark the beginning and end of each
line with perpendicular hatch (||) marks. Write the letters “GC” beside each
line.

3.5.4.2 Geographic Offsets
The Census Bureau is aware that many governments base their legal boundaries on cadastral
(parcel-based) right-of-way mapping. The Census Bureau bases its maps on spatial data that is
topologically integrated. This makes the maintenance of geographic offsets inefficient.
Delineating a government boundary on the centerline wherever applicable will help to establish
more accurate population counts. If a boundary is on the front-lot-line adjacent to a road on
the map, the Census Bureau strongly prefers that the boundary be delineated on the road
centerline already shown on the map. If a boundary is on the rear or side lot line, then it should
be depicted as such. If it is unclear whether a particular line is a front-lot-line or something else,
please contact the Census Bureau for assistance. Generally, if a house or other building could
not conceivably be built in the area between the potential line and the centerline of the road,
then the line can be considered a front-lot-line.
Figure 13 shows a situation in which the place boundary is along the front-lot-line. In this
example, the respondent must either delineate the boundary on the road centerline or create
an offset. In Figure 14, the place boundary is on the rear-lot-line, so the respondent should not
delineate it on the road centerline or create an offset; instead, the respondent should delineate
a new edge that actually follows the rear-lot-line.

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Figure 13. (Left) The Place Boundary is Along the Front-lot-line
Figure 14. (Right) The Place Boundary is on the Rear-lot-line

To indicate a geographic offset on the map, use the red pencil to draw a line parallel to the
road, along which the offset will be created. Mark the beginning and end of the line with
perpendicular hatch (||) marks. Write the letters “OFF” on the side of the road where the
geographic offset exists (Figure 15).

Figure 15. Depicting a Geographic Offset on a Paper Submission

3.5.5

New Incorporations

Newly incorporated places should provide the Census Bureau with:
•
•
•

3.5.6

A copy of the official new incorporation papers, including date of incorporation.
A map indicating the boundaries of the new incorporation.
Contact information for the HEO and a contact for the BAS.

Disincorporations

Disincorporated governments should provide the Census Bureau with a copy of the official
papers of disincorporation, including the effective date.

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3.5.7

Tribal Subdivisions

The Census Bureau considers any type of unit of self-government or administration in tribal
areas as a tribal subdivision. A tribe may submit only one type of subdivision, even if it has
more than one type of distinct administrative area that could qualify as a tribal subdivision
(e.g., tribal election districts, tribal water districts, or health service areas with different
boundaries). The Census Bureau recognizes two types of tribal subdivisions - active (A) or
inactive (I):
•
•

Active subdivisions are defined as having a functioning government, with elected officials, that
provides programs and services.
Inactive subdivisions have no functioning government or elected officials and receive services
solely from the tribe.

a) Some examples of areas submitted as tribal subdivisions are:
o

•

•
•

Areas used by a tribe for the election of tribal government officials (e.g., districts or
precincts used for the election of tribal council members).
o Areas used by a tribal government for tax purposes.
Areas used by a tribal government for the provision of general services or specified services,
such as:
o Water districts.
o Health service areas.
o Emergency service delivery areas (911, fire, and/or police).
o Grazing districts or range units.
Historical or traditional areas recognized by a tribal government.
Sub-reservation tribal community governments.

b) Keep the following criteria in mind when defining tribal subdivisions:
o
o
o
o
o

o

o

U.S. Census Bureau

Tribal subdivisions should cover all, or most, of a tribe’s land base.
The delineation of tribal subdivisions is restricted to the area contained within
reservations and/or associated off-reservation trust lands.
There is no minimum population threshold for a tribal subdivision.
A tribal subdivision may be noncontiguous.
Tribes may designate only one type of tribal subdivision. If a tribe has more than one
level of tribal subdivision within its land base, the Census Bureau recommends
delineating subdivisions corresponding to the lowest geographic level (those geographic
areas containing the smallest area) of the tribe’s administrative hierarchy.
Tribal subdivisions should not be based solely on land ownership or other cadastral
areas, nor should they consist of divisions based on the U.S. Public Land Survey System
(PLSS) of townships, ranges, and sections, if these areas have no governmental or
administrative function for a tribe.
The following descriptions can be appended to chosen subdivision names (e.g., Red
Rock Community):
a) District.
b) Community.
c) Area.
d) Chapter.
e) Segment.
f) Administrative Area.
g) Addition.
h) County District.
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3.5.7.1 Tribal Subdivision Program Procedures
If this is the first time that tribal subdivisions are being provided to the Census Bureau
(Figure 16):
•
•
•
•

Note:

Using the blue pencil, please add the boundaries on the BAS map(s).
Please note: each tribal subdivision must be labeled on each map sheet with its name (e.g.,
“District 3,” “Arlee District,” “White Rock Chapter,” “Parmelee Community”).
Record the name, type, and status of each subdivision in the Tribal Names and Status
Documentation section of the BAS-5 form.
If a tribal subdivision boundary follows a visible feature such as a stream, road, or fence line,
please be sure to indicate that on the BAS map. Add the visible feature the boundary follows if it
is not already shown on the map.
If a full set of BAS maps has not been sent, please request them by calling the Census Bureau at
1-800-972-5651.

Figure 16. Recording New Tribal Subdivision Information
Depicting a new tribal subdivision and recording the information in the
Tribal Names and Status Documentation section of the BAS form.

3.5.7.2 Updating Existing Tribal Subdivisions
If tribal subdivisions were delineated during a prior survey, they are symbolized on the enclosed
BAS maps by a dashed pentagon-shaped gold line. Before adding or revising tribal subdivision
boundaries on the enclosed map(s):
•
•
Note:

Using the red pencil, please note any changes to the boundary of the land base on the map(s).
Using the blue pencil, please add and/or revise the boundaries of the tribal subdivisions on the
enclosed BAS map(s).
The names and types (active or inactive) of tribal subdivisions are listed in the Tribal Names and
Status Documentation section of the BAS-5 form. This information should be reviewed and
updated.

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3.5.7.3 Tribal Subdivision Documentation
New tribal subdivisions and name changes to existing tribal subdivisions require
documentation, regardless of whether they are being delineated for the first time or being
added to those previously reported. This documentation should be in the form of a tribal
resolution or a tribal constitution. Include a copy of this documentation with the BAS maps and
BAS-5 form when returning these materials to the Census Bureau.
Corrections to the Census Bureau’s depiction of tribal subdivision boundaries or names do not
require documentation. If there are any questions or if additional maps are needed, please
contact the Census Bureau at 1-800-972-5651.

3.5.8

County Review and Consolidations

Counties receive boundary information from the Census Bureau for all governments within
their county boundary. Counties should review the names and legal status of active and inactive
incorporated places and MCDs found on page 3 of the BAS-2 form.
•
•

Active governments are defined as having a functioning government, with elected officials, that
provides programs and services.
Inactive governments have no functioning government or elected officials, receive services
solely from the county, and should be reviewed by the county during BAS.

Although it is not required, counties may update boundaries for incorporated places and MCDs
on the county BAS maps. The Census Bureau encourages counties to establish Consolidated BAS
(CBAS) agreements with local governments in order to consolidate resources, reduce the
burden on local governments, and avoid duplication of work. Under a CBAS agreement, the
county is responsible for reporting boundary changes to the Census Bureau. Participating local
governments would no longer receive an annual BAS package. One hundred percent
participation is not required, and governments may opt out of the agreement at any time.
Contact the Census Bureau at for more information on participating in a
CBAS agreement or visit the CBAS webpage at.

3.5.9

Public Land Survey System

Boundaries are often based on nonvisible features, such as Public Land Survey System (PLSS)
lines (i.e. township, section, range lines, etc.). The Census Bureau is currently working on a
program through which PLSS lines can be incorporated into the MAF/TIGER system. If any of
the government’s existing or new boundaries are known to follow PLSS lines, this should be
designated on the BAS submission by writing “PLSS” in red pencil next to (and parallel to) the
appropriate boundary segments. In areas where the Census Bureau has obtained accurate PLSS
shapefiles, the Census Bureau will then be able to compare these lines to those shapefiles and
ensure accurate placement of the boundary.

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PART 4

FEATURE MODIFICATIONS

The primary purpose of the BAS is to collect legal boundary information. However, please also
submit feature (e.g. streets, rivers) updates and modifications occurring near or coincident with
a legal boundary through the BAS. Feature modifications that are internal to the boundary of an
incorporated place, county or MCD will be accepted, but are not required as part of the BAS.

Modifying Locations of Streets
The following figures illustrate how to correct the location of a street feature:
•
•
•

Using the purple pencil, please cross out the incorrect feature location with “Xs”.
Please draw the feature in the correct location.
Please print the name of the feature along the length of the feature as shown in
Figure 17 and Figure 18.

Figure 17. Modifying a Street Feature, No Boundary Movement
In this example, the street location moves, but the boundary does not.

Figure 18. Modifying a Street Feature with Boundary Movement
In this example, both the street location and the boundary move.

The Census Bureau recently completed a nationwide program to improve the positional
accuracy of all streets and other features that appear in the Census Bureau’s MAF/TIGER
System. It is not necessary to make small positional corrections on the BAS maps; correct only
those streets that are incorrectly located, mislabeled or distorted. Additionally, new streets
may be added, and nonexistent streets may be deleted.

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4.1.1
•
•
•
•

Adding Streets
Using the purple pencil, please draw the feature and its name on the map.
Where possible, please provide the address range for any new streets.
Please provide the MAF/TIGER Feature Class Code (MTFCC) (See Appendix B) for all new streets
(Figure 19).
Alternate street names may be written in parentheses below the primary street name.

Figure 19. Adding an MTFCC Code When Adding a New Street

Note:

Due to the difficulty of showing multiple names for a street, only the primary street name is
shown on BAS maps. Please note that, even though alternate street names are not shown on
the maps, they do exist in our database. For example, US Hwy 30 may be locally known as Main
St., but on the BAS map, only US Hwy 30 will be displayed; however, within our MAF/TIGER
System, both names are listed. If an alternate street name has been reported in the past, it
does not need to be reported to the Census Bureau again.

4.1.2

Adding Street Names in a Congested Area

•

•

If an area of the map is too congested to add all feature names, using the purple pencil, please
number each feature and list this number and the corresponding feature name in the map
margin or in an uncongested spot close to the feature’s actual location (Figure 20).
Do not repeat numbers on a map sheet.

Figure 20. Adding Street Name Features in a
Congested Area When Adding Streets

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4.1.3
•
•

Correcting Street Names
Using the purple pencil, please draw a line through the incorrect street name.
Please print the correct street name along the feature.

Figure 21. Correcting a Street Name

4.1.4
•
•
•

Deleting Streets
Delete street features only if they are nonexistent, or impassable. Do not delete a street
because the local jurisdiction is not responsible for maintaining it.
Using the purple pencil, please mark the beginning and end of the base feature to be deleted
with hatch (//) marks perpendicular to the feature as shown below.
Cross-out the nonexistent street feature using a string of “Xs”.

Figure 22. Deleting a Street Feature

4.1.5
•
•

Labeling Unnamed Streets
Using the purple pencil, please label any unnamed streets on the maps.
Label any unnamed private roads with “PR”. Examples of private roads are driveways and
unnamed roads in commercial or industrial parks.

Figure 23. Adding Unnamed Road Features

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4.1.6
•
•
•
•

Adding Cul-De-Sacs or Circles
Using the purple pencil, please draw the feature as follows:
Cul-de-sacs are entirely paved and should be drawn as a solid dot.
Circles have an area of unpaved ground within them and should be drawn as an unfilled circle.
Print the name of the associated street leading to the cul-de-sac or circle.

Figure 24. Adding Cul-de-sac and Circle Features

Annotating Address Range
Addresses are stored in the Census Bureau spatial database as potential address ranges. The
BAS maps show the break in the potential address range created where a street is bisected by a
boundary. These address range breaks are shown because it is important that the Census
Bureau assign the correct addresses to each government.
Note:

Some streets on the BAS maps do not display address breaks due to space considerations.

Add address ranges on both ends of the street only if one of the following circumstances exists:
1. A road where house numbers, street names, and/or addresses were added or deleted.
2. A street was added that crosses a boundary.
3. The address ranges created by a boundary are incorrect on the map.

4.2.1

When Adding Address Ranges

Using the purple pencil, please add in the address ranges, providing the lowest and/or highest
possible addresses where the road intersects a boundary.

Figure 25. Adding Street Feature/Annotating with
Name and Address Breaks

Point Landmarks
BAS maps display a select number of point landmarks (e.g., mountain peaks). Point landmarks
can be updated through BAS but are not required.
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Acceptable point landmark feature updates include mountain peaks or summits, libraries, city
halls, community centers and police stations. Airports, parks, schools, golf courses, museums,
and cemeteries may be submitted as point landmarks or area landmarks.
Features that contain residences or private business should not be added as point landmarks or
area features (e.g. hotels, campgrounds, retirement homes, farms).
The BAS maps also include select point landmarks (e.g. airports, cemeteries, summits) taken
from USGS topography maps and the USGS Geographic Names Information System (GNIS).
These landmarks represent the official federally recognized name and will not be removed or
updated without USGS verification. When adding a point landmark:
•
•

Using the purple pencil, place a solid dot at the location of the point landmark.
Print the name of the landmark next to the dot.

Figure 26. Adding a Point Landmark

Area Landmarks
The BAS maps display a select number of area landmarks (e.g., lakes). Like point landmarks,
area landmarks can be updated through the BAS, but are not required.
Acceptable area landmark updates include water bodies, swamps, quarries, national parks and
forests. Airports, parks, schools, golf courses, museums, and cemeteries may be submitted as
area landmarks or point landmarks.
Features that contain residences or private business should not be added as point landmarks or
area features (e.g. hotels, campgrounds, retirement homes, farms). When adding an area
landmark:
•
•

Using the purple pencil, draw the area landmark boundary in the correct location.
Print the name of the landmark inside or next to the feature.

Figure 27. Adding an Area Landmark

U.S. Census Bureau

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PART 5

RETURNING UPDATES TO THE CENSUS BUREAU

Return all maps with updates using the provided postage-paid return envelope included with
your materials. To obtain a post-paid return envelope, contact the Census Bureau at
or 1-800-972-5651, or mail the updated maps to the Census Bureau at
the address listed below.
U.S. Census Bureau
National Processing Center
ATTN: BAS Returns, Bldg 63E
1201 East 10th Street
Jeffersonville, IN 47132

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APPENDICES

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APPENDIX A ADDITIONAL DOCUMENTATION OF CHANGES FORMS
A1 Places

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A-1

A2 Counties and Equivalent Areas

U.S. Census Bureau

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A-2

A3 Minor Civil Divisions

U.S. Census Bureau

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A-3

A4 Reservations and Off-Reservation Trust Land

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APPENDIX B MTFCC DESCRIPTIONS
The MAF/TIGER Feature Classification Code (MTFCC) is a 5-digit code assigned by the Census
Bureau to classify and describe geographic objects or features in Census Bureau MAF/TIGER
system.
MTFCC
C3022

Feature Class

Feature Class Description

C3023

Mountain Peak or
Summit
Island

C3024

Levee

C3026

C3027

Quarry (not waterfilled), Open Pit Mine or
Mine
Dam

C3061

Cul-de-sac

C3062

Traffic Circle

C3066
C3067
C3070

Gate
Toll Booth
Tower/Beacon

C3071
C3072

C3073

Lookout Tower
Transmission Tower
including cell, radio and
TV
Water Tower

C3074

Lighthouse Beacon

C3075

Tank/Tank Farm

C3076

Windmill Farm

C3077

Solar Farm

C3078

Monument or Memorial

C3079
C3080

Boundary Monument
Point
Survey Control Point

C3081

Locality Point

C3085

Alaska Native Village
Official Point

U.S. Census Bureau

A prominent elevation rising above the surrounding level of the Earth’s
surface.
An area of dry or relatively dry land surrounded by water or low
wetland [including archipelago, atoll, cay, hammock, hummock, isla,
isle, key, moku and rock].
An embankment flanking a stream or other flowing water feature to
prevent overflow.
An area from which commercial minerals are or were removed from
the Earth; not including an oilfield or gas field.
A barrier built across the course of a stream to impound water and/or
control water flow.
An expanded paved area at the end of a street used by vehicles for
turning around. For mapping purposes, the Census Bureau maps it only
as a point feature.
A circular intersection allowing for continuous movement of traffic at
the meeting of roadways.
A movable barrier across a road.
A structure or barrier where a fee is collected for using a road.
A manmade structure, higher than its diameter generally used for
observation, storage, or electronic transmission.
A manmade structure, higher than its diameter, used for observation.
A manmade structure, higher than its diameter, used for electronic
transmission.
A manmade structure, higher than its diameter, used for water
storage.
A manmade structure, higher than its diameter, used for transmission
of light and possibly sound generally to aid in navigation.
One or more manmade structures, each higher than its diameter, used
for liquid (other than water) or gas storage or for distribution activities.
One or more manmade structures used to generate power from the
wind.
One or more manmade structures used to generate power from the
sun.
A manmade structure to educate, commemorate, or memorialize an
event, person, or feature.
A material object placed on or near a boundary line to preserve and
identify the location of the boundary line on the ground.
A point on the ground whose position (horizontal or vertical) is known
and can be used as a base for additional survey work.
A point that identifies the location and name of an unbounded locality
(e.g., crossroad, community, populated place or locale).
A point that serves as the core of an Alaska Native village and is used in
defining Alaska Native village statistical areas.

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C3088
G2100

Landfill
American Indian Area

G2101

American Indian Area
(Reservation Only)
American Indian Area
(Off-Reservation Trust
Land Only)
Hawaiian Homeland
Alaska Native Village
Statistical Area

G2102

G2120
G2130

A disposal facility at which solid waste is placed on or in the land.
A legally defined state- or federally recognized reservation and/or offreservation trust land (excludes statistical American Indian areas).
American Indian Area (Reservation Only)
American Indian Area (Off-Reservation Trust Land Only)

G2140

Oklahoma Tribal
Statistical Area

G2150

State-designated Tribal
Statistical Area

G2160

Tribal Designated
Statistical Area

G2170

American Indian Joint
Use Area
Alaska Native Regional
Corporation

G2200

G2300

Tribal Subdivision

G2400

Tribal Census Tract

G2410

Tribal Block Group

G3100

Combined Statistical
Area

G3110

Metropolitan and
Micropolitan Statistical
Area

U.S. Census Bureau

A legal area held in trust for the benefit of Native Hawaiians.
A statistical geographic entity that represents the residences,
permanent and/or seasonal, for Alaska Natives who are members of or
receiving governmental services from the defining legal Alaska Native
Village corporation.
A statistical entity identified and delineated by the Census Bureau in
consultation with federally recognized American Indian tribes that have
no current reservation but had a former reservation in Oklahoma.
A statistical geographic entity identified and delineated for the Census
Bureau by a state-appointed liaison for a state-recognized American
Indian tribe that does not currently have a reservation and/or lands in
trust.
A statistical geographic entity identified and delineated for the Census
Bureau by a federally recognized American Indian tribe that does not
currently have a reservation and/or off-reservation trust land.
An area administered jointly and/or claimed by two or more American
Indian tribes.
Corporate entities established to conduct both business and nonprofit
affairs of Alaska Natives pursuant to the Alaska Native Claims
Settlement Act of 1972 (Public Law 92-203). There are twelve
geographically defined ANRCs and they are all within and cover most of
the State of Alaska (the Annette Island Reserve-an American Indian
reservation-is excluded from any ANRC). The boundaries of ANRCs
have been legally established.
Administrative subdivisions of federally recognized American Indian
reservations, off-reservation trust lands, or Oklahoma tribal statistical
areas (OTSAs). These entities are internal units of self-government or
administration that serve social, cultural, and/or economic purposes
for the American Indians on the reservations, off-reservation trust
lands, or OTSAs.
A relatively small and permanent statistical subdivision of a federally
recognized American Indian reservation and/or off-reservation trust
land, delineated by American Indian tribal participants or the Census
Bureau for the purpose of presenting demographic data.
A cluster of census blocks within a single tribal census tract delineated
by American Indian tribal participants or the Census Bureau for the
purpose of presenting demographic data.
A grouping of adjacent metropolitan and/or micropolitan statistical
areas that have a degree of economic and social integration, as
measured by commuting.
An area containing a substantial population nucleus together with
adjacent communities having a high degree of economic and social
integration with that core, as measured by commuting. Defined using
whole counties and equivalents.

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G3120

Metropolitan Division

G3200

Combined New England
City and Town Area
New England City and
Town Metropolitan and
Micropolitan Statistical
Area
New England City and
Town Division

G3210

G3220

G3500

Urban Area

G4000

State or Equivalent
Feature

G4020

County or Equivalent
Feature

G4040

County Subdivision

G4050

Estate

G4060
G4110

Subbarrio (Subminor
Civil Division)
Incorporated Place

G4120

Consolidated City

G4210

Census Designated Place

G4300

Economic Census Place

U.S. Census Bureau

A county or grouping of counties that is a subdivision of a Metropolitan
Statistical Area containing an urbanized area with a population of 2.5
million or more.
A grouping of adjacent New England city and town areas that have a
degree of economic and social integration, as measured by commuting.
An area containing a substantial population nucleus together with
adjacent communities having a high degree of economic and social
integration with that core, as measured by commuting. Defined using
Minor Civil Divisions (MCDs) in New England.
A grouping of cities and towns in New England that is a subdivision of a
New England City and Town Area containing an urbanized area with a
population of 2.5 million or more.
Densely settled territory that contains at least 2,500 people. The
subtypes of this feature are Urbanized Area (UA), which consists of
50,000 + people and Urban Cluster, which ranges between 2,500 and
49,999 people.
The primary governmental divisions of the United States. The District of
Columbia is treated as a statistical equivalent of a state for census
purposes, as is Puerto Rico.
The primary division of a state or state equivalent area. The primary
divisions of 48 states are termed County, but other terms are used such
as Borough in Alaska, Parish in Louisiana, and Municipio in Puerto Rico.
This feature includes independent cities, which are incorporated places
that are not part of any county.
The primary divisions of counties and equivalent features for the
reporting of Census Bureau data. The subtypes of this feature are
Minor Civil Division, Census County Division/Census Subarea, and
Unorganized Territory. This feature includes independent places, which
are incorporated places that are not part of any county subdivision.
Estates are subdivisions of the three major islands in the United States
Virgin Islands (USVI).
Legally defined divisions (subbarrios) of minor civil divisions (barriospueblo and barrios) in Puerto Rico.
A legal entity incorporated under state law to provide general-purpose
governmental services to a concentration of population. Incorporated
places are generally designated as a city, borough, municipality, town,
village, or, in a few instances, have no legal description.
An incorporated place that has merged governmentally with a county
or minor civil division, but one or more of the incorporated places
continues to function within the consolidation. It is a place that
contains additional separately incorporated places.
A statistical area defined for a named concentration of population and
the statistical counterpart of an incorporated place.
The lowest level of geographic area for presentation of some types of
Economic Census data. It includes incorporated places, consolidated
cities, census designated places (CDPs), minor civil divisions (MCDs) in
selected states, and balances of MCDs or counties. An incorporated
place, CDP, MCD, or balance of MCD qualifies as an economic census
place if it contains 5,000 or more residents, or 5,000 or more jobs,
according to the most current data available.

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G5020

Census Tract

G5030

Block Group

G5040

Tabulation Block

G5200

Congressional District

G5210

State Legislative District
(Upper Chamber)

G5220

State Legislative District
(Lower Chamber)

G5240

Voting District

G5400

Elementary School
District
Secondary School
District
Unified School District

G5410
G5420
G6100

Public-Use Microdata
Area

G6300

Traffic Analysis District

G6320

Traffic Analysis Zone

G6330

Urban Growth Area

G6340

ZIP Code Tabulation
Area (Three-Digit)
ZIP Code Tabulation
Area (Five-Digit)

G6350
U.S. Census Bureau

Relatively permanent statistical subdivisions of a County or equivalent
feature delineated by local participants as part of the Census Bureau’s
Participant Statistical Areas Program.
A cluster of census blocks having the same first digit of their four-digit
identifying numbers within a Census Tract. For example, block group 3
(BG 3) within a Census Tract includes all blocks numbered from 3000 to
3999.
The lowest-order census defined statistical area. It is an area, such as a
city block, bounded primarily by physical features but sometimes by
invisible city or property boundaries. A tabulation block boundary does
not cross the boundary of any other geographic area for which the
Census Bureau tabulates data. The subtypes of this feature are Count
Question Resolution (CQR), current, and census.
The 435 areas from which people are elected to the U.S. House of
Representatives. Additional equivalent features exist for state
equivalents with nonvoting delegates or no representative. The
subtypes of this feature are 106th, 107th, 108th, 109th, and 111th
Congressional Districts, plus subsequent Congresses.
Areas established by a state or equivalent government from which
members are elected to the upper or unicameral chamber of a state
governing body. The upper chamber is the senate in a bicameral
legislature, and the unicameral case is a single house legislature
(Nebraska).
Areas established by a state or equivalent government from which
members are elected to the lower chamber of a state governing body.
The lower chamber is the House of Representatives in a bicameral
legislature.
The generic name for the geographic features, such as precincts,
wards, and election districts, established by state, local, and tribal
governments for the purpose of conducting elections.
A geographic area within which officials provide public elementary
grade-level educational services for residents.
A geographic area within which officials provide public secondary
grade-level educational services for residents.
A geographic area within which officials provide public educational
services for all grade levels for residents.
A decennial census area with a population of at least 100,000 or more
persons for which the Census Bureau provides selected extracts of
household-level data that are screened to protect confidentiality.
An area delineated by Metropolitan Planning Organizations (MPOs)
and state Departments of Transportation (DOTs) for tabulating
journey-to-work and place-of-work data. A Traffic Analysis District
(TAD) consists of one or more Traffic Analysis Zones (TAZs).
An area delineated by Metropolitan Planning Organizations (MPOs)
and state Departments of Transportation (DOTs) for tabulating
journey-to-work and place-of-work data.
An area defined under state authority to manage urbanization that the
Census Bureau includes in the MAF/TIGER® System in agreement with
the state.
An approximate statistical-area representation of a U.S. Postal Service
(USPS) 3-digit ZIP Code service area.
An approximate statistical-area representation of a U.S. Postal Service
(USPS) 5-digit ZIP Code service area.

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G6400

Commercial Region

H1100

Connector

H2025

Swamp/Marsh

H2030
H2040
H2041
H2051

Lake/Pond
Reservoir
Treatment Pond
Bay/Estuary/Gulf/Sound

H2053
H2060
H2081

Ocean/Sea
Gravel Pit/Quarry filled
with water
Glacier

H3010

Stream/River

H3013

Braided Stream

H3020

Canal, Ditch or Aqueduct

K1121

Apartment Building or
Complex
Trailer Court or Mobile
Home Park
Crew-of-Vessel Location

K1223
K1225
K1226

K1228

Housing
Facility/Dormitory for
Workers
Hotel, Motel, Resort,
Spa, Hostel, YMCA or
YWCA
Campground

K1229

Shelter or Mission

K1231

Hospital/Hospice/Urgent
Care Facility
Nursing Home,
Retirement Home, or
Home for the Aged
County Home or Poor
Farm
Juvenile Institution

K1227

K1233

K1234
K1235

U.S. Census Bureau

For the purpose of presenting economic statistical data, municipios in
Puerto Rico are grouped into commercial regions.
A known, but nonspecific, hydrographic connection between two
nonadjacent water features.
A poorly drained wetland, fresh or saltwater, wooded or grassy,
possibly covered with open water [includes bog, cienega, marais, and
pocosin].
A standing body of water that is surrounded by land.
An artificially impounded body of water.
An artificial body of water built to treat fouled water.
A body of water partly surrounded by land [includes arm, bight, cove
and inlet].
The great body of salt water that covers much of the earth.
A body of water in a place or area from which commercial minerals
were removed from the Earth.
A body of ice moving outward and down slope from an area of
accumulation; an area of relatively permanent snow or ice on the top
or side of a mountain or mountainous area [includes ice field and ice
patch].
A natural flowing waterway [includes anabranch, awawa, branch,
brook, creek, distributary, fork, kill, pup, rio, and run].
A natural flowing waterway with an intricate network of interlacing
channels.
An artificial waterway constructed to transport water, to irrigate or
drain land, to connect two or more bodies of water, or to serve as a
waterway for watercraft [includes lateral].
A building or group of buildings that contain multiple living quarters
generally for which rent is paid.
An area in which parking space for house trailers is rented, usually
providing utilities and services.
A point or area in which the population of military or merchant marine
vessels at sea are assigned, usually being at or near the home port pier.
A structure providing housing for a number of persons employed as
semi-permanent or seasonal laborers.
A structure providing transient lodging or living quarters, generally for
some payment.
An area used for setting up mobile temporary living quarters (camp) or
holding a camp meeting, sometimes providing utilities and other
amenities.
A structure providing low-cost or free-living quarters established by a
welfare or educational organization for the needy people of a district.
One or more structures where the sick or injured may receive medical
or surgical attention [including infirmary].
A structure to house and provide care for the elderly.

One or more structures administered by a local government that serve
as living quarters for the indigent.
A facility (correctional and non-correctional) where groups of juveniles
reside; this includes training schools, detention centers, residential
treatment centers and orphanages.

Boundary Annexation Survey (BAS) Respondent Guide: Paper

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K1236

Local Jail or Detention
Center

K1237

Federal Penitentiary,
State Prison, or Prison
Farm
Other Correctional
Institution

K1238

K1239

K2100

Convent, Monastery,
Rectory, Other Religious
Group Quarters
Sorority, Fraternity, or
College Dormitory
Governmental

K2146

Community Center

K2110

Military Installation

K2165

Government Center

K2167

Convention Center

K2180

Park

K2181

National Park Service
Land
National Forest or Other
Federal Land

K1241

K2182

K2183

Tribal Park, Forest, or
Recreation Area

K2184

State Park, Forest, or
Recreation Area
Regional Park, Forest, or
Recreation Area

K2185

K2186

County Park, Forest, or
Recreation Area

K2187

County Subdivision Park,
Forest, or Recreation
Area
Incorporated Place Park,
Forest, or Recreation
Area
Private Park, Forest, or
Recreation Area

K2188

K2189

U.S. Census Bureau

One or more structures that serve as a place for the confinement of
adult persons in lawful detention, administered by a local (county,
municipal, etc.) government.
An institution that serves as a place for the confinement of adult
persons in lawful detention, administered by the federal government
or a state government.
One or more structures that serve as a place for the confinement of
adult persons in lawful detention, not elsewhere classified or
administered by a government of unknown jurisdiction.
One or more structures intended for use as a residence for those
having a religious vocation.
One or more structures associated with a social or educational
organization that serve as living quarters for college students.
A place where employees are employed in federal, state, local, or tribal
government.
A meeting place used by members of a community for social, cultural,
or recreational purposes.
An area owned and/or occupied by the Department of Defense for use
by a branch of the armed forces (such as the Army, Navy, Air Force,
Marines, or Coast Guard), or a state-owned area for the use of the
National Guard.
A place used by members of government (either federal, state, local, or
tribal) for administration and public business.
An exhibition hall or conference center with enough open space to host
public and private business and social events.
Parkland defined and administered by federal, state, and local
governments.
Area—National parks, National Monuments, and so forth—under the
jurisdiction of the National Park Service.
Land under the management and jurisdiction of the federal
government, specifically including areas designated as National Forest,
and excluding areas under the jurisdiction of the National Park Service.
A place or area set aside for recreation or preservation of a cultural or
natural resource and under the administration of an American Indian
tribe.
A place or area set aside for recreation or preservation of a cultural or
natural resource and under the administration of a state government.
A place or area set aside for recreation or preservation of a cultural or
natural resource and under the administration of a regional
government.
A place or area set aside for recreation or preservation of a cultural or
natural resource and under the administration of a county
government.
A place or area set aside for recreation or preservation of a cultural or
natural resource and under the administration of a minor civil division
(town/township) government.
A place or area set aside for recreation or preservation of a cultural or
natural resource and under the administration of a municipal
government.
A privately owned place or area set aside for recreation or preservation
of a cultural or natural resource.

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K2190

K2191
K2193
K2194
K2195
K2196
K2300
K2361

Other Park, Forest, or
Recreation Area (quasipublic, independent
park, commission, etc.)
Post Office

K2400

Fire Department
Police Station
Library
City/Town Hall
Commercial Workplace
Shopping Center or
Major Retail Center
Industrial Building or
Industrial Park
Office Building or Office
Park
Farm/Vineyard/Winery/
Orchard
Other Employment
Center
Transportation Terminal

K2424
K2432

Marina
Pier/Dock

K2451

Airport or Airfield

K2452
K2453

Train Station, Trolley or
Mass Transit Rail Station
Bus Terminal

K2454

Marine Terminal

K2455

Seaplane Anchorage

K2456

K2459

Airport—Intermodal
Transportation
Hub/Terminal
Airport—Statistical
Representation
Park and Ride
Facility/Parking Lot
Runway/Taxiway

K2460

Helicopter Landing Pad

K2540

University or College

K2362
K2363
K2364
K2366

K2457
K2458

U.S. Census Bureau

A place or area set aside for recreation or preservation of a cultural or
natural resource and under the administration of some other type of
government or agency such as an independent park authority or
commission.
An official facility of the U.S. Postal Service used for processing and
distributing mail and other postal material.
Fire Department.
Police Station.
Library.
City/Town Hall.
A place of employment for wholesale, retail, or other trade
A group of retail establishments within a planned subdivision sharing a
common parking area.
One or more manufacturing establishments within an area zoned for
fabrication, construction, or other similar trades.
One or more structures housing employees performing business,
clerical, or professional services
An agricultural establishment where crops are grown and/or animals
are raised, usually for food.
A place of employments not elsewhere classified or of unknown type.
A facility where one or more modes of transportation can be accessed
by people or for the shipment of goods; examples of such a facility
include marine terminal, bus station, train station, airport and truck
warehouse.
A place where privately owned, light-craft are moored.
A platform built out from the shore into the water and supported by
piles. This platform may provide access to ships and boats, or it may be
used for recreational purposes.
A manmade facility maintained for the use of aircraft [including
airstrip, landing field and landing strip].
A place where travelers can board and exit rail transit lines, including
associated ticketing, freight, and other commercial offices.
A place where travelers can board and exit mass motor vehicle transit,
including associated ticketing, freight, and other commercial offices.
A place where travelers can board and exit water transit or where
cargo is handled, including associated ticketing, freight, and other
commercial offices.
A place where an airplane equipped with floats for landing on or taking
off from a body of water can debark and load.
A major air transportation facility where travelers can board and exit
airplanes and connect with other (i.e. non-air) modes of transportation.
The area of an airport adjusted to include whole 2000 census blocks
used for the delineation of urban areas.
A place where motorists can park their cars and transfer to other
modes of transportation.
A fairly level and usually paved expanse used by airplanes for taking off
and landing at an airport.
A fairly level and usually paved expanse used by helicopters for taking
off and landing.
A building or group of buildings used as an institution for postsecondary study, teaching, and learning [including seminary].

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K2543

School or Academy

K2545

K2561
K2564

Museum, Visitor Center,
Cultural Center, or
Tourist Attraction
Golf Course
Amusement Center

K2582

Cemetery

K2586

Zoo

K3544

Place of Worship

L4010

Pipeline

L4020

Powerline

L4031

Aerial Tramway/Ski Lift

L4110

Fence Line

L4121
L4125

Ridge Line
Cliff/Escarpment

L4130

Point-to-Point Line

L4140

Property/Parcel Line
(Including PLSS)

L4150

Coastline

L4165

Ferry Crossing

P0001

P0002

Nonvisible Linear
Legal/Statistical
Boundary
Perennial Shoreline

P0003

Intermittent Shoreline

U.S. Census Bureau

A building or group of buildings used as an institution for preschool,
elementary or secondary study, teaching, and learning [including
elementary school and high school].
An attraction of historical, cultural, educational or other interest that
provides information or displays artifacts.
A place designed for playing golf.
A facility that offers entertainment performances or sporting events.
Examples include arena, auditorium, theater, stadium, coliseum,
racecourse, theme park, fairgrounds, and shooting range.
A place or area for burying the dead [including burying ground and
memorial garden].
A facility in which terrestrial and/or marine animals are confined within
enclosures and displayed to the public for educational, preservation,
and research purposes.
A sanctified place or structure where people gather for religious
worship; examples include church, synagogue, temple, and mosque.
A long tubular conduit or series of pipes, often underground, with
pumps and valves for flow control, used to transport fluid (e.g., crude
oil, natural gas), especially over great distances.
One or more wires, often on elevated towers, used for conducting
high-voltage electric power.
A conveyance that transports passengers or freight in carriers
suspended from cables and supported by a series of towers.
A man-made barrier enclosing or bordering a field, yard, etc., usually
made of posts and wire or wood, used to prevent entrance, to confine,
or to mark a boundary.
The line of highest elevation along a ridge.
A very steep or vertical slope [including bluff, crag, head, headland,
nose, palisades, precipice, promontory, rim and rimrock].
A line defined as beginning at one location point and ending at
another, both of which are in sight.
This feature class may denote a nonvisible boundary of either public or
private lands (e.g., a park boundary) or it may denote a Public Land
Survey System or equivalent survey line.
The line that separates either land or Inland water from Coastal,
Territorial or Great Lakes water. Where land directly borders Coastal,
Territorial or Great Lakes water, the shoreline represents the Coastline.
Where Inland water (such as a river) flows into Coastal, Territorial or
Great Lakes water, the closure line separating the Inland water from
the other class of water represents the Coastline.
The route used to carry or convey people or cargo back and forth over
a waterbody in a boat.
A legal/statistical boundary line that does not correspond to a
shoreline or other visible feature on the ground.
The more-or-less permanent boundary between land and water for a
water feature that exists year-round.
The boundary between land and water (when water is present) for a
water feature that does not exist year-round.

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P0004

Other non-visible
bounding Edge (e.g.,
Census water boundary,
boundary of an aerial
feature)
Railroad Feature (Main,
Spur, or Yard)
Carline, Streetcar Track,
Monorail, Other Mass
Transit
Cog Rail Line, Incline Rail
Line, Tram

R1011
R1051
R1052

S1100

Primary Road

S1200

Secondary Road

S1400

Local Neighborhood
Road, Rural Road, City
Street

S1500

Vehicular Trail (4WD)

S1630

Ramp

S1640

S1720

Service Drive usually
along a limited access
highway
Walkway/Pedestrian
Trail
Stairway

S1730

Alley

S1740

S1780
S1820

Private Road for service
vehicles (logging, oil
fields, ranches, etc.)
Internal U.S. Census
Bureau use
Parking Lot Road
Bike Path or Trail

S1830

Bridle Path

S2000

Road Median

S1710

S1750

Note:

A bounding Edge that does not represent a legal/statistical boundary
and does not correspond to a shoreline or other visible feature on the
ground. Many such Edges bound area landmarks, while many others
separate water features from each other (e.g., where a bay meets the
ocean).
A line of fixed rails or tracks that carries mainstream railroad traffic.
Such a rail line can be a main line or spur line, or part of a rail yard.
Mass transit rail lines (including lines for rapid transit, monorails,
streetcars, light rail, etc.) that are typically inaccessible to mainstream
railroad traffic and whose tracks are not part of a road right-of-way.
A special purpose rail line for climbing steep grades that is typically
inaccessible to mainstream railroad traffic. Note that aerial tramways
and streetcars (which may also be called “trams”) are accounted for by
other MTFCCs and do not belong in R1052.
Primary roads are generally divided, limited-access highways within the
interstate highway system or under state management, and are
distinguished by the presence of interchanges. These highways are
accessible by ramps and may include some toll highways.
Secondary roads are main arteries, usually in the U.S. Highway, State
Highway or County Highway system. These roads have one or more
lanes of traffic in each direction, may or may not be divided, and
usually have at-grade intersections with many other roads and
driveways. They often have both a local name and a route number.
Generally, a paved non-arterial street, road, or byway that usually has a
single lane of traffic in each direction. Roads in this feature class may
be privately or publicly maintained. Scenic park roads would be
included in this feature class, as would (depending on the region of the
country) some unpaved roads.
An unpaved dirt trail where a four-wheel drive vehicle is required.
These vehicular trails are found almost exclusively in very rural areas.
Minor, unpaved roads usable by ordinary cars and trucks belong in the
S1400 category.
A road that allows controlled access from adjacent roads onto a limited
access highway, often in the form of a cloverleaf interchange. These
roads are unaddressable and do not carry a name in the MAF/TIGER
System.
A road, usually paralleling a limited access highway, that provides
access to structures along the highway. These roads can be named and
may intersect with other roads.
A path that is used for walking, being either too narrow for or legally
restricted from vehicular traffic.
A pedestrian passageway from one level to another by a series of
steps.
A service road that does not generally have associated addressed
structures and is usually unnamed. It is located at the rear of buildings
and properties and is used for deliveries.
A road within private property that is privately maintained for service,
extractive, or other purposes. These roads are often unnamed.
Internal U.S. Census Bureau use.
The main travel route for vehicles through a paved parking area.
A path that is used for manual or small, motorized bicycles, being
either too narrow for or legally restricted from vehicular traffic.
A path that is used for horses, being either too narrow for or legally
restricted from vehicular traffic.
The unpaved area or barrier between the carriageways of a divided
road.

The information in this table was last updated in November 2020.

U.S. Census Bureau

Boundary Annexation Survey (BAS) Respondent Guide: Paper

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APPENDIX C READING A MAP
C1 Index Maps
In order to decide what map to use for the BAS submission, it is necessary to view the
government as a whole and choose the correct parent map sheet based on its location within
the government. Do this by referring to the index map (Figure 28), a relatively small-scale map
that shows the entire government, and the location and number of all parent map sheets
within that government. Each parent map sheet has a numerical locator, which differentiates it
from the other parent map sheets associated with that government. The numbering begins
with the northern and western-most parent map sheets, and continues left-to-right, in much
the same pattern as words in a book. By referring to the index map, determine which parent
map sheet(s) to use for the BAS submission, and then access it based on its number on the
index map.

Figure 28. Index Map
The Index Map sheet shows the location of all parent map sheets and inset
map sheets within a government.

The index map is not appropriate for BAS submissions. Its purpose is as a reference or index of
parent maps, and it will not be accepted as a BAS submission.
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C2 Parent Maps
Many governments, such as incorporated places and counties, are too large to be shown on a
single map; that is, the scale is too small to allow the necessary details for BAS updates. Thus, it
is necessary to separate the government into sections, each of which has its own map, called
the parent map sheet2 (Figure 29). Thus, a single government is often represented with
numerous map sheets, with each parent map sheet showing a small section of the government.
Each parent map is assigned a number, beginning with the number one and increasing
progressively for each additional parent map sheet (i.e. 1, 2, 3, 4, etc.). In this way, viewing and
editing map sheets becomes more manageable, and it becomes possible to depict an area with
the level of detail necessary to make changes or challenges. In most instances, the parent map
is the one that should be used for BAS submissions.

Figure 29. The Parent Map
The parent map sheet shows a section of a government
at a relatively large scale.

In the bottom right-hand corner of the parent map sheet, there is a key to the parent map
sheet’s location in relation to adjacent map sheets as shown in Figure 29 above. A larger
example of this key is shown in Figure 30. This key helps the user quickly determine which
adjacent map sheet to use.

2

Within the scope of BAS, the terms ‘map’ and ‘map sheet’ have the same meaning, and they are used interchangeably throughout this
document.
U.S. Census Bureau

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Figure 30. The Key to Adjacent Sheets
The key to adjacent sheets shows where the parent map sheet lies in
relation to adjacent sheets.

Next to the key to adjacent sheets, there is a small outline of the entire government (the inside
of which is colored yellow), and a blue outline of the parent map sheet. This key displays the
location of the map sheet in relation to the government as a whole as is shown in Figure 31.

Figure 31. The Sheet Location within Government key
The sheet location within government key shows where the parent map
sheet is located within the government to which it belongs.

C3 Inset Maps
In some instances, in highly congested areas, even a parent map sheet provides insufficient
detail for BAS purposes. In such cases, rather than using a parent map, the area is depicted
within an inset map (Figure 32). This refers to a map with a very large scale, so that it displays a
smaller area than the parent map sheet, but with greater detail. On the index map, an inset
map is represented by a green outline, and is assigned a number preceded by a letter (i.e. A1,
A2, B1, etc.), as shown in Figure 33 Inset maps are only found in areas with a large number of
features, and as such are used less often than parent maps.

U.S. Census Bureau

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Figure 32. An Inset Map as it is Displayed on the Index Map

Figure 33. Inset Maps
Inset maps show areas of relative congestion at a large scale, allowing a
greater amount of detail.

C4 Scales
A map is a paper or digital representation of an area. Naturally, the map is always smaller than
the area it represents, so nearly all maps are equipped with a scale, which depicts the ratio of
distance on the map to the actual distance on land. The scale can be designed any number of
ways, but two of the most common scales are ratio scales (Figure 34), which describe a ratio
between the map and the real world (e.g., 1: 24,000), and bar scales, which depict that
relationship graphically by displaying how much a certain distance on the map represents in the
real world (Figure 34). In other words, if a map has a ratio scale of 1: 24,000, it means that one
inch on the map represents 24,000 inches on the ground. (This works with any unit of
measurement, so long as the unit being used on the map is the same as – or properly converted
from – the unit being depicted on the ground.) Often a map will have both types of scale.
U.S. Census Bureau

Boundary Annexation Survey (BAS) Respondent Guide: Paper

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Figure 34. Bar Scale
The map from which this scale was taken has a ratio scale of 1:12,500. The
bar scale shows distances in kilometers and miles.

A bar scale will often be a set length (e.g., one inch), and/or represent a set distance (e.g., one
mile). The bar scale is used to determine distance on the map by using a ruler. Simply place the
ruler on the map to determine the distance on the map; then place the ruler along the bar
scale, which will show how much that distance represents on the ground.
Maps that display a small area, but with a relatively large amount of detail, are considered
large-scale maps (see Figure 35). A map that displays a large area, but shows less detail,
is called a small-scale map. This is because the representative fraction of a large-scale map
(e.g., 1/7,500 or 1:7,500) is a larger fraction than that of a small-scale map (e.g., 1/250,000 or
1:250,000).

Figure 35. Large Scale Map
A large-scale map shows a greater amount of detail; this example displays
streets, parks, churches and restaurants.

C5 Compass Rose
All maps should have some sort of diagram depicting at least one – but sometimes all – of the
cardinal directions (north, south, east, and west) that the map reader can use to orient the
map. This diagram is called a compass rose (see Figure 36). A compass rose can have any
number of designs, and north can be shown in any direction on the map, but most maps are
oriented with north at the top of the map. It is important to check the compass rose when
beginning to read a map, in order to determine the direction in which the map is oriented
(i.e., which direction is at the top of the map).

Figure 36. Compass Rose

U.S. Census Bureau

Boundary Annexation Survey (BAS) Respondent Guide: Paper

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C6 Legend
Because a map is a graphic representation of a real-world area, it is necessary, and convenient,
to symbolize real world features with representative symbols. These symbols can take any
form, so long as they are consistent within any individual map. In order to describe what each
symbol means, most maps have a legend (see Figure 37). The legend is typically located on the
side or bottom of the map, although they can be anywhere so long as they do not obstruct the
integral parts of the map. Typically, the legend will have a small example of each symbol (e.g. a
line, or a picture of a tent), and next to the symbol, in text, a brief description of what is being
depicted (e.g. “road”, or “campground”).

Figure 37. Legend Describing What Each Symbol Means

Sometimes a map needs to depict multiple features concurrently. This is because some lines are
the boundaries of multiple geographies at the same time (i.e. a county boundary can also be a
city boundary, a voting district boundary, and even a highway or river). Such instances can be
depicted in various ways, but Census Bureau maps depict coincident lines by alternating the
symbols for each type of line as shown in Figure 38 below. In other words, if a line is both a
county boundary (symbolized by a series of squares) and a city boundary (a series of circles),
that boundary will be depicted as a series of alternating squares and circles for the length of the
concurrency.

U.S. Census Bureau

Boundary Annexation Survey (BAS) Respondent Guide: Paper

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Figure 38. Map Depicting Multiple Features Concurrently
In this case, the city and the county boundaries are coincident, and run
through the middle of the river.

In situations where higher-level geographies (e.g. national, state, county, or county
subdivisions) coincide, the Census Bureau’s maps display only the symbol of the highest-ranking
of these boundaries. In other words, if a particular boundary is shared by both a state and
county, only the symbol representing the state boundary will be displayed.

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